1. Field of the Invention
The present invention relates to an exposure control apparatus, an image forming apparatus, and an exposure control method.
2. Description of the Related Art
In an electrophotographic image forming apparatus performing exposure process using an LEDA (light-emitting diode array), a line interval in a sub-scanning direction is determined by relationship between a generation cycle of an HSYNC signal representing exposure (write) start timing for one line and a conveying speed of paper. If the above relationship is mismatched, the image expands or shrinks in the sub-scanning direction, which results in uneven density and positional deviation. Accordingly, for example, Japanese Patent Application Laid-open No. 11-010940 discloses a technique for adjusting a generation cycle of an HSYNC signal with respect to a conveying speed of paper.
However, when the generation cycle of the HSYNC signal is changed according to the above conventional technique, the light-emitting time per line changes, which changes the light-emitting time per pixel, and the line cycle changes, which changes the pixel interval in the sub-scanning direction, whereby this affects the image quality.
Therefore, there is a need to provide an exposure control apparatus, an image forming apparatus, and an exposure control method capable of reducing the adverse influence on the image quality and achieving high quality printing.